Fail2ban jail.local vs jail.conf
Solution 1:
According to the Manual 8 0
"Every .conf file can be overridden with a file named .local. The .conf file is read first, then .local, with later settings overriding earlier ones. Thus, a .local file doesn't have to include everything in the corresponding .conf file, only those settings that you wish to override. Modifications should take place in the .local and not in the .conf. This avoids merging problem when upgrading. These files are well documented and detailed information should be available there."